Dialog: Add icons option to support titlebar icons

Fixes #15121

Author: scottgonzalez

tests/unit/dialog/common.js

@@ -18,6 +18,9 @@ common.testWidget( "dialog", {
 		draggable: true,
 		height: "auto",
 		hide: null,
+		icons: {
+			title: null
+		},
 		maxHeight: null,
 		maxWidth: null,
 		minHeight: 150,

themes/base/dialog.css

@@ -27,6 +27,15 @@
 	overflow: hidden;
 	text-overflow: ellipsis;
 }
+.ui-dialog .ui-dialog-title-icon {
+	position: absolute;
+	left: 0.3em;
+	top: 50%;
+	margin-top: -10px;
+}
+.ui-dialog-title-icon + .ui-dialog-title {
+	padding-left: 10px;
+}
 .ui-dialog .ui-dialog-titlebar-close {
 	position: absolute;
 	right: .3em;

ui/widgets/dialog.js

@@ -58,6 +58,9 @@ $.widget( "ui.dialog", {
 		draggable: true,
 		hide: null,
 		height: "auto",
+		icons: {
+			title: null
+		},
 		maxHeight: null,
 		maxWidth: null,
 		minHeight: 150,
@@ -404,7 +407,7 @@ $.widget( "ui.dialog", {
 	},
 
 	_createTitlebar: function() {
-		var uiDialogTitle;
+		var uiDialogTitle, uiDialogTitleIcon;
 
 		this.uiDialogTitlebar = $( "<div>" );
 		this._addClass( this.uiDialogTitlebar,
@@ -446,6 +449,12 @@ $.widget( "ui.dialog", {
 		this._addClass( uiDialogTitle, "ui-dialog-title" );
 		this._title( uiDialogTitle );
 
+		if (this.options.icons.title) {
+			uiDialogTitleIcon = $( "<span>" ).prependTo( this.uiDialogTitlebar );
+			this._addClass( uiDialogTitleIcon, "ui-dialog-title-icon",
+				"ui-icon " + this.options.icons.title );
+		}
+
 		this.uiDialogTitlebar.prependTo( this.uiDialog );
 
 		this.uiDialog.attr( {